Unable to extrude SVG inside Blender
Extruding vertices, edges or faces can only be done with meshes.
SVGs are by default Curves not mesh objects, a different kind of object, with different properties.

For 2d curves use the Geometry->Extrude options.



For further transformations you might need to convert the object to mesh. On the "Object" menu choose "Convert to" -> Mesh From Curve/Meta/Surf/Text.